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Biomedical subjects

D C Desai

Publications and source records attributed to D C Desai.

At least 19 recordsLinked to original sources
PubMed2001

18F-labeled fluorodeoxyglucose positron emission tomography-guided surgery for recurrent colorectal cancer: a feasibility study.

OBJECTIVE: Positron emission tomography (PET) scanning is an accepted diagnostic tool for the detection of colorectal cancer (CRC). The purpose of this study was to determine whether diagnostic information offered by preoperative PET scan could be used to detect disease intraoperatively using beta and gamma handheld probes. METHODS: Two studies were carried out. First, tumor "phantoms" were created using 62 microCi fluorodeoxyglucose (FDG) in a saline-filled basin. Gamma and beta handheld probes were used to determine detection characteristics with respect to probe type, distance from source, and isotope half-life. In a second study, probes were used intraoperatively to detect tumor in 10 patients with recurrent colorectal cancer as determined by preoperative PET scan. Counts relative to background were determined for each probe as was histopathologic correlation with probe-positive tissue. RESULTS: Phantom studies documented that FDG detection by each probe was nonlinearly related to source proximity and half-life. In human subjects, abnormal findings on preoperative PET studies were detected by both probes with tumor:normal ratios of 1.6 (beta) and 1.5 (gamma). All probe-positive tissue was histologically confirmed to be recurrent colorectal cancer. CONCLUSIONS: Intraoperative detection of CRC using an FDG source and beta and gamma probes correlates with preoperative PET. With further improvements in probe technology, successful differentiation of normal and tumor tissue as shown here may allow for more precise localization and directed resection.

Beta Particles↗
PubMed2001

Serum pancreastatin levels predict response to hepatic artery chemoembolization and somatostatin analogue therapy in metastatic neuroendocrine tumors.

INTRODUCTION: Neuroendocrine tumors often metastasize to the liver and present with disabling hormonal symptoms. Hepatic artery chemoembolization (HACE) combined with somatostatin therapy, pre-embolization, peri-embolization and post-embolization, at doses to control symptoms, is an aggressive approach that can relieve hormonal symptoms with minimal morbidity and mortality. METHODS: Chemoembolization was performed using 30 mg of adriamycin, 50 mg of mitomycin, 12 ml of hexabrix, 10 ml of ethiodol, and 360-500-microm particles. Pancreastatin, a split product of chromogranin A, was measured pre-HACE and post-HACE in all patients. RESULTS: Forty-three chemoebolization procedures were performed in 34 symptomatic patients from December 1995 to August 1999. Seventeen patients had intestinal primaries (50%), seven had pancreatic primaries (20%), five had bronchial primaries (15%), and five had unknown primaries (15%). Systemic pancreastatin levels were improved or stable in 31 patients (78%). Symptoms were improved in these 31 patients (78%). Systemic serotonin levels were improved or stable in 24 patients (60%). Radiographic improvement or stability was seen in 18 patients (45%). Procedural related morbidity included pain, fevers, nausea, vomiting, and transient elevations of liver function studies in 75-100% of patients. There was one procedural related mortality (2%). Less than 20% improvement in pancreastatin levels from baseline was associated with death in five of five patients (100%). This was not observed with serotonin levels. CONCLUSION: Measurement of serum pancreastatin levels is an easy and useful method to predict success in patients who undergo HACE plus somatostatin therapy for metastatic neuroendocrine tumors to the liver. This therapeutic approach is effective in relieving symptoms in 78% of patients, with minimal major morbidity or mortality.

Adult↗
PubMed2000

Recurrent germline mutation in MSH2 arises frequently de novo.

INTRODUCTION: An intronic germline mutation in the MSH2 gene, A-->T at nt942+3, interferes with the exon 5 donor splicing mechanism leading to a mRNA lacking exon 5. This mutation causes typical hereditary non-polyposis colorectal cancer (HNPCC) and has been observed in numerous probands and families world wide. Recurrent mutations either arise repeatedly de novo or emanate from ancestral founding mutational events. The A-->T mutation had previously been shown to be enriched in the population of Newfoundland where most families shared a founder mutation. In contrast, in England, haplotypes failed to suggest a founder effect. If the absence of a founder effect could be proven world wide, the frequent de novo occurrence of the mutation would constitute an unexplored predisposition. METHODS: We studied 10 families from England, Italy, Hong Kong, and Japan with a battery of intragenic and flanking polymorphic single nucleotide and microsatellite markers. RESULTS: Haplotype sharing was not apparent, even within the European and Asian kindreds. Our marker panel was sufficient to detect a major mutation arising within the past several thousand generations. DISCUSSION: As a more ancient founder is implausible, we conclude that the A-->T mutation at nt942+3 of MSH2 occurs de novo with a relatively high frequency. We hypothesise that it arises as a consequence of misalignment at replication or recombination caused by a repeat of 26 adenines, of which the mutated A is the first. It is by far the most common recurrent de novo germline mutation yet to be detected in a human mismatch repair gene, accounting for 11% of all known pathogenic MSH2 mutations.

Colorectal Neoplasms, Hereditary Nonpolyposis↗
PubMed1998

The utility of the Hartmann procedure.

BACKGROUND: In 1923 the French surgeon Henri Hartmann described an operation for rectosigmoid cancer as an alternative to abdomino-perineal resection for high-risk patients. In the subsequent years, the indications for performing the Hartmann procedure have broadened to include complicated diverticulitis, ischemic bowel, iatrogenic perforations, volvulus, and colitis. METHODS: We have retrospectively reviewed our experience in 185 patients who underwent the Hartmann procedure from January 1981 to December 1995. Charts were reviewed for indications, morbidity, and mortality and to determine the outcome of patients who underwent the Hartmann procedure. RESULTS: The main indications for performing the Hartmann procedure were complicated diverticulitis (including perforation, obstruction, and abscesses) in 108 patients, rectosigmoid cancer in 31 patients, and other indications in 46 patients. There were a total of 27 deaths for an in-hospital mortality of 14%. All complications occurred at a rate of less than 9%. Of the 158 surviving patients, 90 (57%) eventually underwent the second stage of the operation to restore bowel continuity. The average length of time between initial resection and reanastomosis was 149 days. There were no deaths associated with the second stage of the procedure and complications occurred at a rate less than 4%. CONCLUSIONS: This is the largest reviewed series of the Hartmann procedure. Mortality is lower than in other reported series, and morbidity is low. Our data demonstrate that the second stage of the procedure, in properly selected individuals, is a procedure that can be performed with minimal morbidity and no mortality. This is different from other published reports. We conclude that the Hartmann procedure is a safe and efficacious option for the surgeon confronted with the complex pathology of the rectosigmoid area, with acceptable morbidity and mortality.

Aged↗
PubMed1998

Pentobarbital affects transepithelial electrophysiological parameters regulated by protein kinase C in rat distal colon.

For rat distal colon, the transepithelial electrical parameters, short circuit current (Iscc) and transepithelial electrical resistance (TER), respectively, measure net transepithelial electrolyte transport activity and the barrier function of the epithelium. Studies with a variety of epithelial cell cultures have shown greater than 90% decreases of TER within minutes of exposure of in vitro cell sheets to phorbol esters. The phorbol ester and protein kinase C (PKC) activator, phorbol dibutyrate (PDBU), was observed to produce an over 100% elevation of Iscc but only a small yet significant 20-30% decrease of TER across rat distal colon. Inhibition of the above effects of PDBU by the PKC inhibitor bisindolylmaleimide (GFX) is further evidence that in rat distal colon, Iscc and TER are under regulatory control by PKC. When animals received anesthesia with intraperitoneal pentobarbital prior to removal of the colon, the effect of PDBU on Iscc was significantly reduced, and the effect of PDBU on TER was almost completely inhibited. This effect of pentobarbital on PKC-mediated transepithelial permeability parameters is consistent with the known ability of anesthetics to alter protein kinase C activity. Exposure of rat colon to pentobarbital produced as much as a 90% inhibition of calcium-dependent PKC activity, whereas calcium-independent activity was stimulated by as much as 35%. Prior anesthetic use may be therefore a complicating factor in observing PKC-mediated effects on epithelial barrier function using epithelial tissue models.

Adjuvants, Anesthesia↗
PubMed1998

A survey of phenotypic features in juvenile polyposis.

Solitary juvenile polyps are quite frequent in children, but juvenile polyposis (JP) is a rare autosomal dominant trait characterised by the occurrence of numerous polyps in the gastrointestinal tract. Extracolonic phenotypic abnormalities are well documented in patients with familial adenomatous polyposis and Peutz-Jeghers syndrome and can allow a clinical diagnosis to be made before the bowel pathology becomes available. Though described, characteristic extracolonic abnormalities have not been clearly defined in juvenile polyposis. We sought to determine whether there are consistent extracolonic phenotypic abnormalities in JP patients and how frequently this would allow diagnosis of one of the genetic syndromes known to be associated with juvenile polyposis. Twenty-two JP patients underwent clinical examination and data from one patient were obtained from case notes. Those consenting to further investigations had x rays of the skull, chest, and hands and an echocardiogram if clinically indicated. Significant extracolonic phenotypic abnormalities were present in 18 patients (14 male and four female), and included dermatological (13), skeletal (16), neurological (5), cardiopulmonary (4), gastrointestinal (3), genitourinary (4), and ocular (1) features. In five patients the diagnosis of a genetic syndrome was possible: two had Bannayan-Riley-Ruvalcaba syndrome, two had Gorlin syndrome, and one had hereditary haemorrhagic telangiectasia (HHT, also known as Osler-Rendu-Weber syndrome). Other patients had some features of these conditions and of Cowden and Simpson-Golabi-Behmel syndromes, but these were not sufficient to allow a definitive diagnosis.

Adult↗
PubMed1997

Wandering spleen: a challenging diagnosis.

Wandering spleen is rare, particularly in children, and diagnosis is difficult. It usually occurs at 20 to 40 years of age, and most cases are seen in women. Diagnosis is difficult because of lack of symptoms, unless splenic torsion has occurred. Patients usually have an asymptomatic abdominal mass, an acute abdomen, or, most commonly, a mass associated with pain. Laboratory data are nonspecific, but the diagnosis can be confirmed by imaging studies; computed tomography and duplex ultrasonography are preferred modalities. Treatment is operative because of complications of splenic infarction and possible splenectomy. Splenopexy is the treatment of choice for a noninfarcted wandering spleen. Splenectomy should be done only when there is no evidence of splenic blood flow after detorsion of the spleen. We review our experience with wandering spleen in two pediatric patients, one treated with splenopexy and the other with splenectomy.

Abdominal Pain↗
PubMed1997

Dilatation of radiation-induced esophageal strictures under sublingual buprenorphine analgesia: a pilot study.

BACKGROUND: Pain during dilatation of radiation strictures is a troublesome complaint. There is little information on sedation and analgesia during this procedure. We performed a pilot study to compare the analgesic efficacy of sublingual buprenorphine and intravenous pentazocine during dilatation of radiation-induced esophageal strictures. METHODS: Thirty-one patients with esophageal cancer who had radiation-induced strictures were randomized to receive either buprenorphine 0.2 mg sublingually two hours before dilatation (n = 17) or pentazocine 30 mg intravenously five minutes before dilatation (n = 14). Dilatation was considered successful if it could be performed to 12 mm diameter or more. Pain experienced during dilatation was graded as mild, moderate or severe. RESULTS: Sixteen patients in the buprenorphine group and 12 in the pentazocine group were dilated to > 12 mm size (p = ns). Twelve and nine patients respectively in the two groups experienced mild or no pain; ten and six patients had minor side-effects (p = ns). CONCLUSION: Buprenorphine is useful for sedoanalgesia during dilatation of radiation-induced strictures of the esophagus.

Administration, Sublingual↗
PubMed1997

Brachial plexus injury due to compression: an alternate mechanism of injury: case report and review of the literature.

We present a case of a brachial plexus injury due to compression of the nerves from a traumatic hematoma, with no associated bone or vascular injury. The paralysis in this case was not evident for 48 hours after the initial injury, implying that the brachial plexus was not damaged directly. Electromyograms documenting brachial plexopathy were obtained. The mechanism of injury in this case is different from the usual mechanisms of injury in brachial plexus trauma. The majority of brachial plexus injuries are associated with multisystem trauma. The mechanism of injury to the brachial plexus is either from extreme traction on the nerves or direct impact. Downward traction generally results in lesions in the upper cervical nerve roots, whereas upward traction results in lesions of the lower cervical nerve roots, C8 and T1. The usual symptoms of brachial plexus injuries include paralysis of the shoulder, arm, and/or hand with parasthesias and altered sensation. Temperature and color of the limb may be altered because of damage to the autonomic nervous system. The treatment of brachial plexus injuries varies depending on the mechanism and the time the injury is discovered in relation to the inciting trauma. Current treatment includes assessing function with physical examination, preoperative electromyogram, and then repair of viable nerve roots and associated vascular injuries.

Axilla↗
PubMed1996

Dilation of proximal esophageal strictures following therapy for head and neck cancer: experience with Savary Gilliard dilators.

BACKGROUND: There is little information on dilation of proximal strictures following surgical and/or radiation therapy for head and neck cancer. We studied the feasibility and efficacy of dilating proximal strictures following therapy for head and neck cancer using Savary Gilliard dilators. METHODS: Twenty-one consecutive patients with proximal strictures resulting from surgery and/or radiation therapy of head and neck cancer were studied. Savary Gilliard dilation was performed using the standard and a modified method. Dysphagia was graded before and after dilation using a 5-point scale. RESULTS: Technical success, dysphagia relief, complications, and duration of relief were noted. Technical success was achieved in 20 (95%) patients. Adequate dysphagia relief was obtained in 15/20 (75%) patients, which lasted for 4-36 weeks (median 14 weeks). There were no perforations, bleeding, or deaths. Four patients required repeat dilation after a median interval of 12 weeks. CONCLUSIONS: Savary Gilliard dilation is a safe and effective method for dilating strictures caused by therapy for head and neck cancer.

Adult↗
PubMed1996

Paget's disease of the male breast.

A histopathologically proven case of Paget's disease of the breast in a 47-year-old male induced a review of the 32 cases in the world's literature. Paget's disease usually presents in the 5th and 6th decades of life without any obvious racial predilections. The most frequent presenting signs include ulceration, eczema, nipple discharge, bleeding, and crust formation. At the time of presentation, 50 per cent of the patients have a palpable breast mass, positive lymph nodes, or both. When entertaining the diagnosis of Paget's disease of the breast using morphologic characteristics of the cells, the diagnosis of malignant melanoma and Bowen's disease (intraepithelial squamous cell carcinoma) must be included in the differential diagnosis. Certain differences will be seen between these three entities based on specific cell staining and the uptake of certain tumor markers. There is no evidence that this disease behaves differently in males versus females, but the 5-year survival for males is worse: 20 to 30 per cent in males versus 30 to 50 per cent in females. The treatment of this disease must focus on the pathology of the underlying tumor. Current treatment involves modified radical mastectomy or radical mastectomy for Stage I and II tumors. Adjuvant chemotherapy, radiation, and tamoxifen are also used depending on the nodal and receptor status of the tumor.

Biopsy↗
PubMed1995

Juvenile polyposis.

Juvenile polyposis is an uncommon condition characterized by the development of multiple juvenile polyps, predominantly in the colon but also in the rest of the gastrointestinal tract. The condition usually presents in childhood; only 15 per cent of patients present as adults. The rarer and often fatal form, namely, juvenile polyposis of infancy, is typified by diarrhoea, protein-losing enteropathy, bleeding and rectal prolapse. The more common form of juvenile polyposis (affecting the colon, stomach and small bowel) occurs in the first or second decade with rectal bleeding and anaemia. A family history of the condition is found in 20-50 per cent of patients with apparently an autosomal dominant trait. The gene for juvenile polyposis has not yet been identified. Epithelial dysplasia is common and the cumulative risk of colorectal cancer is > 50 per cent. Various extracolonic abnormalities may also occur. Most patients are treated surgically for colonic polyps, although endoscopic polypectomy is also an option. The rest of the gastrointestinal tract should be screened as should asymptomatic first-degree relatives.

Adenomatous Polyposis Coli↗
PubMed1995

Dilation of difficult gastrointestinal strictures using a modified wire-guided technique.

We describe here 18 patients with gastrointestinal strictures through which a standard guide wire could not be passed, and which were dilated using a modified technique. After a 0.035" guide wire had been passed through a 5-Fr metal-tipped catheter, the narrow strictures were dilated using a 10-Fr biliary dilator. A modified Savary-Gilliard guide wire (olive-tipped with a hole) was passed over the 0.035" guide wire beyond the stricture. After removing the 0.035" guide wire, the strictures were dilated with Savary-Gilliard dilators passed over the olive-tipped guide wire. Seventeen patients had upper gastrointestinal strictures, and one had a sigmoid colon stricture. The strictures were caused by tumor in two, radiation therapy in six, esophagogastric resection for cancer in five, and a combination of two or more factors in five patients. The modified technique was successful in 17 patients, without any complications. Adequate symptomatic relief was achieved in 15 patients.

Adult↗